Abstract
OBJECTIVE: To investigate the long-term safety and efficacy of high-dose radiotherapy after 3D-printed vertebral body implantation in the treatment of spinal tumors. METHODS: Thirty-three participants were recruited between July 2017 and August 2019. 3D-printed vertebral bodies were implanted in each participant, followed by postoperative robotic stereotactic radiosurgery at a dose of 35-40 Gy/5f. The tolerance of the 3D-printed vertebral body and the participant to the high-dose radiotherapy were evaluated. In addition, the local control of tumor and the local progression-free survival of the study participants following 3D-printed vertebral body implantation and high-dose radiotherapy were measured as indexes of effectiveness. RESULTS: Of the 33 participants included in the study, 30, including three participants (10%) with esophagitis of grade 3 or above and two participants (6.7%) with advanced radiation nerve injury, successfully underwent postoperative high-dose radiotherapy. The median follow-up was 26.7 months, and IQR was 15.9 months. Most participants had primary bone tumors with 27 cases (81.8%), and the rest had bone metastases in six cases (18.2%). After high-dose radiotherapy, the 3D-printed vertebrae maintained good vertebral stability and exhibited histocompatibility, without implant fractures. The local control rates were 100%, 88%, and 85% 6 months, 1 year, and 2 years after high-dose radiotherapy, respectively. Tumors recurred in four participants (12.1%) during the follow-up period. The median local progression-free survival after treatment was 25.7 months, with a range of 9.6-33.0 months. CONCLUSION: High-dose radiotherapy for spinal tumors after 3D-printed vertebral body implantation is feasible, elicits low toxicity, and yields satisfactory tumor control.